Oil burner control system



y 3 1933- J. V.'BREISKY ET AL I 1,911,347

OIL BURNER CONTROL SYSTEM Filed Aug. 22; 1928 5 sheets-sheep 1 fi'gti. v 3

John [Ere/5K and 7750/1705 Drop er:

BY V

ATTORNEY May 30, 1933.

J. v. BREIS KY ET AL OIL BURNER CONTROL SYSTEM Filed ug. 22, 1928 3 Sheets-Sheet 2 INVENTOR5 J'ohn WB/e/5A and 77100705 Draper.

' ATi'ORNEY y- 1933- J. v. BREISKY ET AL 1,911,347

OIL BURNER CONTROL SYSTEM FiledAug. 22, 1928 "s Sheets-Sheet 3 3/ INVENTORS John 1/. Brae/sky and Thomas Draper:

' ATTORNEY Patented May 30, 1933 UNITED STATES PATENT OFFICE JOHN V. BREISKY, OF PITTSBURGH, AND THOMAS DRAPER, 0F SWISSVALE, PENNSYL- VANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC A CORPORATION OF PENNSYLVANIA AND MANUFACTURING COMPANY,

OIL BURNER CONTROL SYSTEM Application filed August 22, 1928.

Our invention relates to oil burners and more particularly to safety control systems therefor.

An object of our invention is toprovide a relatively simple and highly eflicient control system for a fuel-burning installation.

Another object of our invention is to provide 'a safety control system that shall be actuated in accordance with the conductivity of a flame of the burning fuel.

Another object of our invention is to pro vide a safety control system for fuel-fired furnaces in which anelectrical-discharge device is made use of to control certain steps of operation of the system.

Another object of our invention is to provide a fuel-burner system embodying one or more safety devices.

Another object of our invention is to provide a fuel-burner system that shallbe applicable to burners using a Variable fuel feed to maintain a predetermined room temperature.

Another object of our invention is to provide a fuel-burner system that shall be effective to reenergize an ignition means without appreciable delay in caseof flame failure for any cause.

Another object of our invention is to provide a quick-acting fuel-burner system in which the fuel-feeding means is shut down in such short time as to prevent dangerous accumulation of fuel in the furnace, in case of faulty ignition or in case the fuel fails to ignite.

Another object of our invention is to provide means in a slow-acting fuel-burner sys tem fortesting the effectiveness of the ignition and for preventing operation of the fuelfeeding means in case the ignition is not such as to properly ignite the fuel.

Another object of our invention is to provide means. in a fuel-burner system, for pre venting trouble in the system resulting from current leakage in a flame terminal.

- Another object of our invention is to provide a fuel-burners system in which a control device is actuated directly by an electrical Serial No. 301,194.

. In practicing our invention, we provide a fuel-burner system embodying means for feeding oil under pressure into a furnace, a motor for driving the fuel-feeding device proper, a room thermostat for initiating the operation of the control system and for controlling the energization of a time-delay circuit interrupter for the motor of the fuelfeeding device, as well as for controlling the energization of an ignition and a control transformer, respectively.

We provide also means for testing the effectiveness of the ignition means before energizing the fuel-feeding means and for deenergizing the ignition means as soon as the fuel has been ignited and is burning properly, as well as a means for testing or checking for terminal leakage.

In the drawings, 1

Figure 1 is a view, partially in side elevation and partially in vertical section, of a fuel-burning furnace and system shown as installed in a house, the control system being shown schematically,

Fig. 2 is a view, in longitudinal section,

vice for measuring the conductivity of a flame of the burning fuel, and

Figs. 3 to 7, inclusive, are diagrams of connections embodying our invention, comprising a number of modifications of the system and different 'instrumentalities employed in connection therewith.

Referring more particularly to Fig. 1 of the drawing, we have there illustrated a room 11 which is to be heated and which is part of a house, represented generally by an outside wall 12, extending to a floor 13 of a basement room 14. p

' A furnace 16 is located in the chamber 14 and may be of any suitable or desired construction for the intended purpose and encloses a furnace chamber 17. One or more hot-air ducts 18 may be provided to permit of hot air entering the room 11. A flue 19 connects the furnace chamber 17 with a chimney 21.

A table or supporting means 22 is pro-.

23 'to which is mechanically coupled an air blower 24 and an oil pump 26. The blower 24 is connected to a suitable conduit 27 extending into the furnace chamber 17. The oil pump 26 has its outlet connected to a conduit 28 which-may be located within the conduit 27 and which also extends into the fur nace chamber 17. The construction of the conduit 28 is such that any oil forced therethrough from a suitable tank (not shown) by the pump 26 will enter the furnace chamber in an atomized condition ready to be burned. VVhile we have shown a specific embodiment of fuel conduit, a pressure blower and a fueloil pump, we do not desire to be limited thereto as these are shown for illustrative purposes onlyand in order to bring out more clearly the details of the control system embodying our invention. T.

Referring more particularly to the control system illustrated in Fig. 1 of the drawings, we provide a source of electric energy comprising supply-circuit conductors 29 and 31. A room thermostat 32, here shown as a simple bimetallic strip, is located in the room 11 and has one of its contact members electrically connected tothe supply-circuit conductor 29 by means of a conductor 33.

The other terminal of the thermostat'32 is connected through a conductor 34, to one termmal of a coil 36 of a time-delay circuit interrupter 35, here shown as a contactor embe disengaged from, a pair of fixed contact members 39. A dash-pot .device 41' is shown as being operatively connected to the core and the contact-bridging member in order to provide a time-delay for the contactor. A. contactor has been shown for purposes of slmplicity and it is to be understood that the contact-bridging member 38 is not disengaged from the contact members 39 as soon as the coil 36 is energized, but only after a predetermined, and preferably adjust-able, time delay. While we have shown a timedelay contactor, we may use a mercury switch embodying substantially the same elements but obtaining the time delay in a somewhat different manner, the essential feature being that the engagement of the movable and fixed contact members shall continue for a predetermined length of time after the actuating coil thereof has] been energized.

The other terminal of the coil 36 is electrically connected to one -of a pair of substantially fixed contact members 42 constituting parts of a relay or electromagnetic circuit interrupter'43. The interrupter 43 comprises, in addition to the substantially fixed contact members 42, a contact-bridging member 44, a core member 46operatively connected to the bridging member and an .actuat- I ductor 54, to one of the fixed contact members 39 of the time-delay circuit interrupter 35 heretofore described.

One terminal of the secondary winding 52 of the ignition transformer is connected to ground, while the other terminal thereof is connected, through a suitably insulated conductor 56, to one electrode 57 ofa spark gap, the other electrode of which is constituted by a suitable member 58 made of metal and secured to the conduit 27. While we have shown a specific embodiment of a spark gap, we do not desire to be limited thereto.

'A high-tension control transformer 59 has one terminal of its primary winding 61 connected to the conductor 54, while the other terminal thereof is connected to the supplycircuit conductor 31. The transformer 59 embodies a core 62 and a secondary winding 63, one terminal of which is connected to asuitable fusible element- 64.

The other terminal of the fusible element 64 is connected to one terminal of an actuating coil 66 of a double-coil contactor, which may be designated generally by the numeral 67. The other terminal of the coil 66 is connected, by a conductor68, to one terminal of the coil 47 of the contactor 43, hereinbefore described, the other terminal of coil 47 being connected to ground. The contactor 67 comprises a core member 69 energized by the coil 66, a second core member 71 adapted to be energized by a coil 72, a contact-bridging member 73 and a plurality of substantially fixed contact members 74 adapted to engage,

or be disengaged from, the bridging member 73. I

One of the contact members 74 and one terminal of the coil 72 are connected, by a conductor 76, to the conductor 54. The other terminal 74 is connected, by a conductor 77, to one terminal of the winding of the motor 23. the other terminal thereof being connected, by a conductor 78, to the supply-circuit conductor 31.

- The other terminal of the coil 72 is connected, through a eonductor 7 9, to a pluralelectrode electrical-discharge device 81 which is so located that it is under the influence of the electric field of the high'frequency current traversing the conductor 56, the secondary winding 52' of the ignition transformer and the spark gap.

The plural-electrode device 81 may be constituted by any one of a number of devices with a rare gas, such as neon. One of the.

charactcristicsof an electrical-discharge device of this kind is that, when not subjected to the influence of a high-frequency electric field, it is electrically non-conducting. When a tube of this kind is subjected to such an electrical field combinin both electromagnetic and electrostatic e ects, it will permitv a current to traverse the tube, provided, of course, it is connected to a suitable source of supply of electric energy.

Referring to the circuit interrupter 43, one of the contact terminals 42 is connected, through a conductor 82, to the supply-circuit conductor 31, or, as shown in Fig. 1, to the conductor 78.

The other terminal of the secondary coil 63 is connected, by a conductor 83, to a control electrode 84. A conductor 86 connects the junction point of the fuse 64 and the coil 66 to electric-conducting tubular element 87 coaxial with, and surrounding, the electrode 84. The member 87 may be of metal or of carbonaceous material, as may be found desirable or necessary.

The elements 84 and 87 are parts of an improved device embodying a part of our invention, and the assembled device is shown in Fig. 2 of the drawings. We have there shown a part of a'wall 88 of the furnace structure 16 having a suitable opening 89 therethrough for receiving the electrode structure. An outer tubular casing 91 which may be of ceramic or other suitable electricinsulating material having a high resistance to leakage of electric current and that will not deteriorate when subjected to relatively high temperatures, as Well as an inner tubular member 92, also of electrlc-insulatmg material. The tubular electric-conducting member 87 is located therebetwen. Thee-lectrode 84 is suitably mounted within the inner tubular element 92, being held therein by a plug 93 which may be of any suitable high-temperature-resisting and electric-insulating material.

The structure embodying the control electrode 84 is adapted to be supported in the opening 89 in any suitable or desired manner,.here shown as by a plurality of ring members 94, which may have a wedging effect between the wall 88 and the tubular member 91. The control electrode is preferably so located that it will extend into the flame of the burning fuel in substantially the manner and to the extent indicated in Fig. 1

' of the drawings.

Referring more particularly to Fig. 3 of the drawings, we have there illustrated a modification of a system embodying our invention, and, while we have not shown the fuel-feeding means, afurnace, and a room to be heated thereby, it is to be understood that these elements are present, as shown and described in connection with Fig. 1 of the drawings.

p A room thermostat 32 has one of its terminals connected to the supply-circuit conductor 29 by a conductor 33, while the other terminal thereof is connected by a conductor 34 to one terminal of a coil 36 of a time-delay circuit interrupter 35, as hereinbefore described. The conductor 34 is also connected to one of the contact terminals 39 of this circuit interrupter. The other terminal of the coil 36 is connected to one of the contact terminals 42 of a circuit interrupter 43, as hereinbefore set forth. One terminal of the primary coil 49 of an ignition transformer 51 is connected to the same contact terminal 42 as is the coil 36, while the other terminal of the coil 49 is connected, through a conductor 96, to one terminal of the primary coil 61 of a control transformer 59, as hereinbefore described. The other terminal of the primary winding 61 is connected to the'su'pply-circuit conductor 31.

One terminal of the secondary winding 63 I is substantially the same as the control elec- I trode 84, as shown inFig. 2 of the drawings, but the tubular electric-conducting member 87 and the tubular insulating member 91, are

not provided therewith. It is to be understood, however, that the control electrode is mounted in "the furnace structure 16 substantially as was hereinbefore set forth in connection with the control electrode 84 in order that the conductivity of the flame of the burning fuel maybe measured and made use of.

One terminal of the secondary coil 52 of the ignition transformer 51 is connected to ground and the other terminal is connected, by a conductor 56, to one electrode 57 cooperating with another electrode 58 to provide a spark gap, as was hereinbefore set forth in connection with Fig. 1 of the drawings.

A plural-electrode electrical-discharge device 81 is provided, as was hereinbefore set forth, and is located to be within the influence of the electric field generated by a high-frequency current traversing the secondary winding 52, the conductor 56 and the electrodes 57 and 58.

One terminal of the tube 81 is connected, by a conductor 101, to a conductor 102 which connects one of the contact terminals 42 of the interrupter 43 to the supply-circuit conductor 31. The other terminal of the tube 81 is connected, by a conductor 79, to one terminal of the coil 7 2 of the plural-coil interrupter 67. The other terminal of the coil 72 is connected, by a conductor 103, to one 'of the contact terminals 39 of the time-delay circult interrupter 35, as well as to one terminal of the primary coil 49 of the ignition trans former and to one terminal of the primary coil of the control transformer 59.

A. conductor 104 connects one of the contact terminals 39, namely, that to which one terminal of the primary coils 49 and 61 and one terminal of coil 7 2 are connected, to one of the contact terminals 74 of the interrupter 67. The other contact terminal 74 is connected to one terminal of the winding of the motor 23, the other terminal of which is connected. through a conductor 106, to the supply-circuit conductor 31.

Referring to Fig. 4 of the drawings, a room thermostat 32 has one terminal connected to the supply-circuit conductor 29,, while the other terminal thereof is connected, by a conductor 107, to one terminal of a latching thermostat 108 embodying, by way of illustration, a bimetallic strip 109, one end of which is fixed and the other end of which may engage,

or he disengaged from a contact terminal.

I The device 108'embodies. in addition to the contact terminals and the bimetallic strip, a heating element or coil lll'and a latching member 112 which is adapted to engage the deflected bimetallic strip 109' and to hold the -same against moving back into its initial position wherein it operatively engages its operating contact member. The latch 112 is adapted to be manually actuated to permit release of the bimetallic strip.

One terminal of the heating element 111 isconnected to that terminal of device 108 to Which is secured the fixed end of the bimetallic strip. The other end of element 111 is connected to a junction point 113. A conduc, tor 114 connects the j unction point 113 to one of apair of substantially fixed lower contact members 116 constituting apart of a contactor 117 and to one of a'pair of upper contact members 118. The contactor 117 embodies also a contact-bridging member 119, an actuating coil 121 and a core member 122, all of usual construction. The other contact member 118 is connected to that terminalof device 108 which has one terminal of heater 111 conne ted thereto.

The other of the lower contact members 116 is electrically connected to one terminal of the primary coil 49 of an ignition transformer 51, the other terminal of the primary coil being connected, through a conductor 123, to the supply-circuit conductor 31. The secondary coil 52 of the ignition transformer 51 has one of its terminals connected to ground, while the other terminal thereof is connected, by a conductor 56, to one electrode 57 of a spark gap embodying a choperating electrode 58, as was hereinbefore set forth.

. A conductor 124 connects the junction point 113 to one terminal of the winding of motor 23, the other terminal of the winding being connected to the supply-circuit conductor 31.

One terminal of a primary winding 61 of a control transformer .59. is connected either to the conductor 114 or directly to the junction The other terminal of the coil 61 is connected, by a conductor-126, to supply-circuit conductor 31.

One terminal of the secondary coil 63 of I the control transformer is-connected, through a conductor 99, to a control electrode 100, as

. was hereinbefore set forth in connection with Fig. 3 of the drawings. The other terminal of coil 63 is connected, by a conductor 127, to one terminal of the actuating coil 121 of the contactor 117, the other terminal of this coil being connected to ground.

Referring more particularly to Fig. 5 of the drawings, a room thermostat 32 has one terminal thereof connected to supply-circuit conductor 29 by a conductor 33. A conductor 34 connects the other terminal thereof to one terminal of a coil 36 of a time-delay contactor 35, as hereinbefore set forth in connection with Figs. 1 and 3. The conductor 34 is effective also to connect one terminal of the room thermostat 32 to one. of the contact members 39 of the. device 35.

The other contact terminal 39 is connected by a conductor 128 to a junction point 129.

This nnction point is connected to one terminal of the primary coil 49 of an ignition transformer 5, to one terminal of the primary coil 61 of the a control transformer 59 and to one terminal of the winding of a motor 23. The other terminal of coil 49 is connected to one of the contact terminals 42 of a contactor 43, the same contact terminal being connected, by a conductor 131, to the other terminal of coil 36. A conductor 132 connects the other One terminal of the secondary coil 63 of the control transformer 59 is connected, by a conductor 133, to the control electrode 84 of g a device, as hereinbefore described in connectionwith Fig. 1. The other terminal of the coil 63 is connected, by a conductor 134, to one terminal of the fusible element 64, the

other terminal of which is connected, respectively, to one terminal of coil 47 and to the tubular electrode 87. The other terminal of coil 47 is connected to ground.

Referring more particularly to Fig. 6 of the drawings, a room thermostat 32 is connected to supply-circuit conductor 29 by a conductor 33. The other terminal of room thermostat 32 is connnected, by a conductor:

other terminal of the heating element 111 is' connected, by a conductor 136, to one of the lower contact terminals 116 and one of the upper contact terminals 118 of a plural-position contactor 117, as was hereinbefore set forth in connection with Fig. 4 of the draw- Ihe conductor. 136 is connected, by a conductor 137, to one terminal of the actuating coil 72 of a plural coil contactor 67, one terminal of the primary coil 61 of a control transformer 59' and to one contact terminal 74 of the contactor 67.

The other terminal of coil 72 is connected, by a conductor 138, to one terminal of a glow tube 81, the other terminal of which is connected, by a conductor 139, to supply-circuit conductor 31. The other terminal of coil 61 is also connected to conductor 31.

One terminal of the secondary coil 63 is connected, by a conductor 99, to a control electrode 100, as hereinbefore set forth in connection with Fig. 3 of the drawings. The

other terminal of winding 63 isconnected to one terminal of coil 66, while the other terminected to the fixed end of strip nal of this coilis connected, by a conductor 141, to one terminal ofcoil 121, the other terminal thereof-being connected to ground. The other terminal 74 of contactor 67 is connected to oneterminal of the winding of motor 23, the other terminal thereof being connected to supply-circuit conductor 31.

That terminal of heating element 111, con- 109, is connected, by a conductor 142, to the other end of the contactterminals 118.

A conductor 143 connects the other contact terminal 116 to one terminal of coil 49 of the ignition transformer 51, the other terminal of this coil being connected to OOH"? before set forth in connection with Fig. 1 of.

the drawings.

A resistor 144 is connected in shunt circuit relation with the primary coil 49 of the ignition transformer for a purpose to be hereinafter set forth in detail.

Referring to Fig. 7 of the drawings, a room thermostat 32 has one of its terminals connected to. supply circuit conductor 29 by a conductor 33. The other terminal thereof is connected, by a conductor 34, to one terminal of coil 36 of a time-delay circuit interrupter 35, as already hereinbefore described. The other terminal of coil 36 is connected, by a conductor 146, to one of the two contact terminals 42 of a contactor 43. The same contact terminal 42 is connected, by a conductor 147, to one terminal of the primary coil 49 of an ignition transformer 51.

The conductor 34 is connected also to one of the two contact terminals 39 of the device 35, the other terminal 39 being connected, by a conductor 148, to the other terminal of coil 49, to one terminal of the primary coil 61 and a to one terminal of the winding of motor 23.

inbefore set forth. One terminal of coil 63.

of the control transformer is connected, by a conductor 149, to one terminal of coil 47, the other terminal of which is connected to ground. The other terminal of coil 63 is connected, by a conductor 99, to a control electrode 100. i

Referring more particularly to Fig. 1 of the drawings, the elements of the system are there shown in their active positions, that is, when the temperature of the room 11 is above a predetermined minimum value, so that the thermostat 32 is in its open position. If the room temperature drops below the predetermined value, the thermostat operates to close an energizing circuit through the coil 36, jbridging member 44, conductors 82 and 78 and to the supply-circuit conductor 31.

[As was hereinbefore set forth, the time-delay circuit interrupter, comprising the coil 36, begins to operate but does not immediately disengage the bridging member 38 from the contact members 39,'so that an energizing circuit is provided forthe primary coil '61 through-the bridging member 38, conductor 54 and through coil 61 to conductor 31. An energizing circuit for the coil 49 may also be traced, through the conductor 54, coil 49, conductor 48, the bridging member 44 of the interrupter 43, and conductors 82 and 78, to supply-circuit conductor 31.

The ignition transformer 51 is thus energized,.and, if the spark gap existing between the electrodes 57 and 58 is of the proper diconductor 76, bridging member 73, conductor mensions, sparking will occur therebetween, and a high-frequency current will flow through the conductor 56, the circuit being,

of course, completed by the ground return.

This energizes the conductor 56 and provides an electric fielditherearound which ionizes the tube 81. The tube 81 may be so located relatively to the conductor 56 that it will be properly ionized or energized only when the electrical condition of the sparking occurring between the electrodes 57 and 58 is such as to insure ignition of the atomized oil when provided by the fuel-feeding means. When the electric discharge device 81 is thus properly ionized, a circuit therethrough will be provided from supply-circuitconductor 29, conductor 33, thermostat 32, conductor 34, contact terminals 39 and bridging mem- 77, Winding of motor 23, and, through conductor 78, to conductor 31. This energizes the motor 23 which starts and, within a short time, delivers atomized fuel oil at the end of conduit 28 and air under pressure at the end of conduit 27.

The atomized oil will, if all conditions are proper, be immediately ignited by the sparking occurring between the electrodes 57 and- 58 and a flame will thus be generated within the furnace chamber 17 whereby hot air or any other heating medium may be furnished to heat the room 11.

If the flame generated by the burning fuel is of suflicient volume,.it will extend toward and engage the properly located electrode 84,

and another circuit will be established, sub- .stantially as follows: From the grounded contact member 74 so long metal parts of the furnace through the flame, electrode 84, conductor 83, coil 63, fuse 64, coil 66, conductor 68, coil 47 and to ground. The energized coil 66 will provide a holding means for insuring that the bridging member 73 remains in operative engagement with the as the flame is of the proper size and conductivity. If the con- 6 struction of the furnace is not-such asto ensure= that the flame will be in operative engagenient with a metal part thereof, we may provide another electrode 151 in the furnace,

Stficture, suitabl grounded and so located as to be engaged y the flame of the burning fuel at all times.

As the current traversing the coil 66 traverses also the coil 47, the core 46 is energized,

and the bridging member 44 is raised and disengaged from the contact members 42. This disengagement has two results, namely, to deenergize the coil 36, and to deenergize'the pri-.

mary winding 49 of the ignition transformer.

It is to be understood that the time delay of the time-delay circuit interrupter 35 is such as to permit ofall of the hereinbeforedescribed operations being effected in proper sequence before the bridging member 38 is disengaged from the contact members 39, it being assumed, of course, that the proper volume of sparks is provided to ignite the oil, and that properly atomized oil is provided within a relatively short time in the manner arcing or sparking takes place between the electrodes 57 and 58, and hence, no current will traverse the conductor 56, and the glow tube 81 will be deenergized, thereby interrupting the current traversing the coil 72 of the plural-coil circuit-closing device 67, but the coil 66- remains energized, as hereinbefore set forth, and insures that the motor circuit will remain closed as long as there is a flame and as demanded by the position of the thermostat 32.

If and when the thermostat reopens in response to the rise in temperature of the'room, the individual devices will return to substantially their positions, shown in Fig. 1 of the drawings and be ready for. restarting, as demanded by the room thermostat 32.

It is possible that excessive leakage will occur between the measuring electrode 84 and the grounded portions of the furnace struc- 'tureand, in order to protect thesecondary coil 63 against excessive current values traversing it because of such leakage, we provide the tubular electric-conducting member 87 therearound and the fuse 64 connected in an electrical circuit, as set forth.

If we assume that a ground exists between the electrode 84 and the surrounding electricconducting parts of the furnace, any current leaving the electrode 84 cannot reach ground without .first flowing through or along the tube 87. This establishes a local circuit as follows: From electrode 84 to the tube 87, through conductor 86, fuse 64, coil 63 and through conductor 83 to electrode 84. It may be noted that the contactor coils 66 and 47 will not be energized, even though the cur rent value traversing this circuit is relatively large, as long as there is no flame.

If the fuel be ignited, the current leaving the electrode 84 may flow in two parallel paths as follows: From electrode 84, through the flame, to ground, coils 47 and 66, fuse 64 and through coil 63, and from electrode 84,

through whatever leakage path there may be 64 should be such that it will not be fused by the current traversing the coils, but will be fused by any current value which is too large for the secondary coil 63.

It may be noted that, if an excessive leakage of current to ground should occur through the control electrode structure while the burner system is in normal operation, the first result would be that the fuse 64 would be blown. The interruption of the supply of energy from the secondarywinding 63 to coils 66 and 47 would also be effected, whereby the contactor 67 would interrupt the supply of energy to the motor 23. The deenergized contactor coil 47 would effect geenergization of the ignition transformer 'If the excessive leakage of current continued, the value of the current traversing the primary windings of the ignition and the control transformer will cause operation of the time delay contactor 35 to deenergize substantially the entire system.

When the system has been rendered inactive by the melting of member 64, it is necessary for an operator to replace the fuse and repair the control electrode after which the system is again ready for operation.

The description given above of the scquenc of operations was based, as mentioned, upon the proper operation of all of the elements embodied in the complete system. It is possible, however, that the sparking will not be such as to effect proper ignition ofthe atomized fuel, by reason of a gap of improper length. If this condition occurs, the high-frequency field ionizing the electrical discharge device 81 ,will not be of 1 such character as to properly ionize the same, particularly if the coupling between the conductor 56 and the device 81 has been properly adjusted in order to insure that the device 81 shall be energized or ionized properly only if and when the sparking is of the proper character to properly ignite the atomized oil.

If the tube 81 should not be sufficiently ionized to permit a current to traverse it, the actuating coil 72 will not be energized and the motor circuit will not be closed in sufii cient'time to prevent operation of the timefrom a few seconds to several minutes, these time limits being for illustrative purpose only and are not to be considered as limiting the operation thereof or of the system in any way. If, therefore, the sparking is not such as would properly. ignite the oil, the time-delay circuit breaker will operate to interrupt the circuit, irrespective, of course, of the position of the thermostat 32.

If it be assumed that the sparking between the electrodes 57 and 58 is of the proper character and that, for some reason or other, the flame is not of the proper character or is not present at all, as in case the fuel does not ignite, the load circuit comprising the flame, the electrode 84, the coil 66 and the Winding 63 would not be effected and the time-delay circuit interrupter would operate to deenergize all portions of the system.

In case of flame failure, as may occur in case of momentary failure of the fuel supply, coils 66 and 47 are immediately deenergized as the normal circuit therethrough is interrupted by cessation of the flame. The

contactor67 will be actuated to its open p0 sition and the contactor 43 will be actuated to its closed position, the coil 36 is again energized and the time element thereof is started. The motor circuit is interrupted and.the ignition means is again energized. The cycle of starting operations is thus again initiated, and if all parts of the system operate properly, the'burner will be opera tive again within a short time.

In case of momentaryjfailure and the re- 3 turn of the power supply, the sequence of operations is the same as would ensue if the room thermostat were to operate to m'omentarily open and then close its circuit.

the drawings, this represents a modified system, differing slightly from that shown in Fig. 1 of the drawings, the sequence of operations being, however, substantially the same.

Referring more particularly to Fig. 3 of Upon closing of the thermostat 32, the coil 36 is energized, through conductors 33 and 34, thermostat 32, coil 36, contact members of the swit'chf43 and conductor 102, to the a I supply circuit. The primary coil 49 is energized, through conductor 33, thermostat 32, conductor 34, bridging member 38, conductor 96, bridging member 44 and conductor 102, to supply-circuit conductor 31.

Another energizing circuit may be considered as starting at conductor 96 and including the coil 61 of the control transformer.

l The energized secondary 52 of the ignition transformer provides the high-frequency discharge between the electrodes 57 and 58.

which, if of theproper characteristic, will suitably ionize the tube 81. This provides an energizing circuit, through conductor 33, thermostat 32, conductor 34, contact-bridging member 38, conductor 103,coil 72, coni ductor 79, tube 81 andconductors 101 and 102, to the supply circuit. This energizes the closing coil 72, whereby a motor energizing circuit is closed comprising conductor 33, thermostat 32, conductor 34, bridging member 38, conductors 96 and 104, bridging member 73, winding of motor 23 and conductor 106 to the supply circuit. 1

This starts the motor, and if the oil is properly supplied and ignited, a control circuit through the flamewill be established. This circuit includes the secondary 63, conductor 97, coil 66, conductor 98, coil 47, to ground, through the flame, control electrode 100 and conductor 99 to the coil 63. This last-named circuit not only establishes a holding circuit for the contactor 67 but also causes upward movement of the bridging member 44 whereby the primary coil of the ignition transformer is deenergized, as is also the coil 36, so that the bridging member 38 will re- 7 tion, the proper volume of sparking will be main n engagement with the contact mem- 'of parallel-connected branch circuits all starting at junction 113. These parallel circuits are, respectively, through conductor 114, bridging member 119, primary coil 49, and conductor 123 to conductor 31; from junction 113, conductor 114, coil 61- and conductor 126 to supply conductor 31; from junction 113, through conduct-or 124, Winding of motor 23, through conductor 126, to supply conductor 31.

This energizes the ignition transformer, and, with all parts in proper operative condi:

provided between cooperating electrodes 57 and 58. The motor 23 is simultaneously started and will, within a very short time, provide fuel in the furnace to be ignited by the fuel-igniting means.

As soon as the flame is present in the furnace, the energized secondary coil 63 of the control transformer 59 will establish a current through a circuit traceable as follows: from one terminal of coil 63. conductor 127, coil 121 to ground, from ground through the flame electrode100, conductor 99 and back to coil 63. This energizes the coil 121 which thereupon operates to move the bridging member 119 upwardly, disengagingit from the contact terminals 116, whereby the ignition transformer is deenergized and rendered inactive.

As soon as the bridging member 119 engages the contact members 118, a shunt cir- V cuit is provided around the coil 111 whereby the same is practically short circuited so that the time delay device 108 is rendered inactive.v This sequence of operations is, of course, based upon the assumption that all of the parts of the system operate properly and within the proper time limits, that is, the sparking between electrodes 57 and 58 is of a proper Volume, the motor operated to provide proper amount of fuel inthe furnace, which fuel was promptly ignited by the fuel-igniting means. The same general remarks as to abnormal conditions of operation apply here, as were made in connecti with Fig. 1 of the drawings.

Referring more particularly to Fig. 5 of the drawings, upon closure of the thermostat 32, a circuit is established from conductor 29 through conductor 33, device 33, conductor 34 and from there, through coil 36, conductor 6 between electrodes 57 and 58, and the motor 23 is effective to provide the proper amount of fuel wi in the furnace chamber which will be ignited by the fuel-igniting means. 1 It is to be noted that bridging member 38 has remained in operative engagement'of contact members 39 during all of this time by reason of the action of the -dash-pot or delay element 41.. If now-,a flame is provided in the furnace chamber, a circuit is established starting at one terminal of coil 63 of the control transformer, including conductor 133, electrode 84, the flame of the burning fuel I and ground return to the grounded terminal of coil 47 and there'- through, fusible element 64 and through conductor 134 to the other terminal of coil 63. This energizes the coil 47, and the bridging member 44 is disengaged from. the contact members 42, whereby the ignition transformer is deenergized, and sparking between electrodes 57 and.58 will stop JThe abnormal conditions of operation are substantially the same as hereinbefore set forth in connection with Fig. 1.

drawings, upon closing of the thermostat 32, a circuit is established from conductor 29 through conductor 33, device32, conductor 107, strip '109, heating element 111 and,

I Referring particularly to Fig. 6 of the a through conductor 136, to a number of parallel-connected branch circuits which may be traced as follows: one branch circuit includes conductor 136, bridging member 119, conductor 143, coil 49 and resistor 144, and, through conductor 139, to supply-circuit conductor 31.= Another branch circuit includes conductor 137, coil 61 and therefrom to supply-circuit conductor- 31.

The energized secondary coil 52 is nor-' mally effective to provide the proper sparking between electrodes 57'and 58' whereby the glow tube 81 is ionized or energized to a .proper degree to permit of a current traversing it and the coil 72 of the contactor 67, whereby the contactor 67 is energized to effect closing of the motor-winding circuit by means of the bridging member 73 engag ing the contact member 74.

This provides asupply of fuel to be burned in the furnace and, under normalconditions, a flame will exist in the furnace chamber.

A holding circuit is established traceable as follows: from one terminal of coil 63 through conductor 99 to electrode 100, the flame of the burning fuel to ground, through coil 121, conductor 141, coil 66 and backto, the other terminal of coil 63.

This causes actuation of the bridging member 119 in an upwardly direction to disengage it from the contact terminals 116 whereby the ignition transformer is deenergized. The engagement of bridging member 119 with contact members 118 effects a shortcircuit of heating element 111, whereby the time-delay device 108 is rendered inactive.

Upon cessation of current flow in the conductor 56 incident to the deenergization of the ignition transformer, the glow tube 81 is also deenergized and current will no longer traverse it, and the coil 72, as was hereinbefore set forth. This has no effect upon the contactor 67, as the winding 66 is nowtraversed by a current which will continue to permit energization of the winding of the motor 23 and, therefore, operation of.the system may continue until controlled by opening of the room thermostat 3 2. The same remarks as to abnormal conditions of Operation, hereinbefore made in connection wiith the system shown in Fig. 1, apply here a so.

Explanation may be here made as'to the reason for the use of resistor 144 connected in parallel-circuit relation to winding 49. If the resistor 144 were not provided and if the primary winding 49 were to be open circuited by reason of damage thereto or if the secondary circuit of the transformer51 were to be entirely interrupted, resulting in a condition of no secondary current I flow through the winding 52, the value of the currenttraversing the circuit including the V 5; heating element 111 will be very small. The

heatgenerated in the element-111 will not be sufiicient to energize the strip 109 to cause it to be actuated to its open position and deenergize other parts of the system, e. g. the control transformer 59. The system will remain in an intermediate condition of operativeness until proper steps are taken by an operator to test theparts and make needed repairs. If the resistor 144 is used, the current traversing the heating element 111 will be relatively large and the strip 109 will be sufficiently heated, even though the current through the transformer 51 be small or be zero, to operate to deenergize the system.

Referring to Fig. 7 of the drawings, a closure of the room thermostat 32 establishes a circuit from contactor 29 through conductor 33, thermostat 32, conductor 34, coil 36, conductor 146, bridging member 44 and from there back to conductor 31.- A branch circuit may be considered as starting at conductor 34 and including bridging member 38, conductor 148 and from there through a plurality of parallel branch circuits. One of these includes coil 49, conductor 147, bridg- 'ing' member 44, back to conductor 31, while a second branch circuit includes coil 61 and from there to conductor 31, while a third branch circuit includes the-winding of motor 23 and from there to conductor 31.

The energization of transformer 51 provides the proper sparking between electrodes 57 and 58, and the energized motor 23 is normally effective to provide a supply of fuel in the furnace chamber. v

As'soon as a flame has been established in the furnace chamber, a control circuit is established including coil 63.- conductor 149', coil 47, a ground return, the /flame of the burning fuel, electrode 100, and conductor 99 back to coil 63. This energizes coil 47 and causes disengagement of the bridging member 44 from the contact terminals 42 where- 4 by the coil 49 is deenergized. This deenerfurther sparking will occur normally between electrodes 57 and 58.

If, as has already been set forth in connection with the operation of time delay device 35, all of these steps in the operation of the system have been effected within the proper time limits, the time-delay device 35 will not have operated to disengage bridging member 38 from contact terminals 39, and, as coil 36 is deenergized by reason of the disengagement of bridging member 44 from contact terminals 42, the time-delay device 35 is rendered inactive and will remain in the position shown in the drawings. v

The system embodying our invention provides means, incertain of its modifications,

of the proper character is the fuel-feeding device energized. The circuits embodying this part of our control system is shown in Figs. 1, 3 and 6, while the other systems illustrated in the other figures of the drawings do not embody this modification.

A number of systems embodying our invention have been illustrated and described, differing in details only, in order to show how the various safety features may be included or omitted in accordance with the degree of safety desired and also whether the burner requires a short time or a long time for being put in operation.

- It may be in order to give a brief resum of what the systems illustrated in the respective figures of the drawings are more particularly designed to accomplish. Referring to Fig. 1, there is-little or no possibility of explosions because of the provision of means for preventing the fuel-feeding means/supplying fuel to the furnace unless the'fueligniting means is in proper operative condition. This system permits of obtaining any desired length of time delay before shut" down of the system is eflected, without introducing any hazards, for the reasonsjust set forth above, thus making it possible to use this system on burners requiring a comparatively long time for starting without aceompanying unnecessary shut-downs of the cause.

tem will shut down in case any trouble develops that would tend to cause an unsafe eonditionf 4 Referring to Fig. 3 of the drawings, the system there shown has substantially the same characteristics as have just been set forth 1n connection with that shown in Fig.

1, with the exception that terminal leakage will not cause a shut down, this being for the reason that a simple control electrode 1s used instea of the more complicated one shown in Fig. 2 of the drawings. However,

such electrode structure may be used, if desired.

The system illustrated in Fig. 4 of the drawings is not provided with a means for checking the operating characteristic of the lgnitlng means, but substantially the same comments apply as were 'madeabove in connection with Fig. 1. 1 i

Substantially the same remarks a ply for the system shown in Fig. 5 of the rawings as were made above in connection with Fig. 1 of the drawings, with the exception that no means is provided for checking the operation of the fuel-igniting meansj Referring to Fig. 6 of the drawings, the system there shown operates in substantially the same manner and has the sameadvantages as were set forth above in connection with the system shown in Fig. 3.

The system shown in Fig. 7 is substantially the same in its operation as that shown in Fig. 4.

It is obvious that the systems embodying our invention may be operated from direct current supply circuits, the ignition and con trol transformers being made in the form of induction coils provided with interrupters, in a manner well known in the art.

It is also obvious that, while we have shown coils 47 and 66 connected in seriescircuit relation to each other, they may be connected in parallel-circuit relation. It is not believed necessary. to illustrate such connection, as its equivalence to the series connection in this case is evident.

The systems illustrated in Figs. 1, 3 and 6 are particularly applicable to fuel-burner systems which require a relatively long time for starting the flame. This is for the reason that the fuel-igniting means is energized initially and is then tested or checked by the means hereinbefore set forth before the fuelfeeding means is energized. The systems shownin Figs. 4, 5 and 7 are particularly applicable to fuel burners having a relatively short time delay.

It is, of course, obvious that the more complicated control electrode structure illustrated in Fig. 2 of the drawings may be used in the systems shown in Figs. 3, 4, 6 so desired.

The control transformer hereinbefore illustrated and described may be substantially the same as the ignition transformer, that is,

it is operable from an ordinary house-lighting and 7, if

circuit and provides a secondary voltage on the order of 10,000 volts. with this secondary voltage on the control transformer that the current therethrough is sufficiently large to permit of the use of We have found substantially standard contactor coils and that the circuit interrupting devices used therewith may be rugged, I

In one element of our system, we provide a means directly associated with the control electrode for testing for excessive leakage between the control electrode and ground portions of the furnace structure immediately operatively engaging the electrode, such means cooperating with other elements of the system to shut down the entire system in case of excessive current leakage.

made relatively strong and It may be noted, in general, that. as long as the system embodying all of the herein described safety features is properly operative in all of its parts for the intended purpose, itwill continue to operate as called for by the demand that it shall control the temperature of a given space, such as a room, within predetermined limits. If any part of the system does not operate properly, it provides its own means for deenergizing the entire system so that an operator can reset or readjust those parts or elements temporarily out of adjustment whereby the system will be again placed in proper operative conditions.

Various modifications may be made in the system embodying our invention without departing from the spirit and scope thereof, and we desire, therefore, that only such limitations shall be placed therein as are imposed by the prior art or are set forth in the appended claims. 4

We claim as our invention:

1. A fuel-burner system comprising a fuelfeeding means, a control circuit including a control electrode normally operatively engaged by the flame of the burning fuel, and

' additional means included in said control circuit. for effecting deenergization of the and said conducting means adjacent to theregion of the flame within said burner and insulated from said burner.

In testimony whereof, we have hereunto subscribed our names this 15th day of August, 1928.

JOHN V. BREISKY. THOMAS DRAPER.

system in case of excessive current leakage from the control electrode to ground.

2. A fuel-burner system comprising a fuelfeeding means, a control circuit comprising a fusible member and a control electrode norm'ally operatively engaged by the flame of -the burning fuel, said fusible member being so connected in the control circuit as to be fused by excessive current leakage from the.

controlielectrode to ground.

3. A fuel-burner system comprising a fuelfeeding means, a control circuit comprising a fusible member and a control electrode normally operatively engaged by the flame of the burning fuel, said fusible member being so connected in the control circuit as to be fused by excessive current leakage from the control electrode to ground and means'for deenergizing the fuel-feeding means upon fusing of said fusible member.

4. A fuel-burner system comprising fuel I V feeding means having a timeelay cut-out associated therewith, fuel-i nition means,

'means associated with said lgnition'means for rendering'said fuel-feeding means oper- I ative, and, in combination with an electric circuit including the ionized gases of the.

flame of said fuel for rendering said ignition means and said time-delay cut-out inoperative, means for rendering said fuel-feeding means inoperative in response to a leakage path other than said flame.' v

5. As an article of manufacture,'a flameelectrode com rising an insulating tubular' casing, a con ucting cylinder supported coaxial with said casing, and an insulating tube supported coaxial said cylinder and said cas- 

